A man has been jailed for a minimum of 17 years after being found guilty of the "chilling, terrible and revolting" murder of a two-year-old boy.
Rio Smedley suffered 91 separate injuries and died from a ruptured liver, Manchester Crown Court heard.
Daniel Rigby, 23, from Tyldesley, Wigan, was found guilty of murdering his girlfriend's son by a jury of six men and six women. Rigby was sentenced to life in prison and ordered to serve a minimum term of 17 years before he would be considered for parole.
Mr Justice David MacKay told him: "The jury has convicted you of the murder of this little boy. You don't need me to tell you what a terrible crime that was."
The judge said Rigby had abused his position of trust. He said: "You abused that trust by punishing him physically in quite a revolting way. It's a chilling, terrible picture. He suffered considerably before he died, I am satisfied. He was a vulnerable boy. You abused your trust."
The judge said he did not think Rigby intended to kill Rio but had a "sudden loss of temper" and "set about him, inflicting the fatal blow". He was murdered on April 22 in what the prosecution said was "a wicked attack on a defenceless two-year-old child".
Rio's mother, Kirsty Smedley, 24, formerly of Cheriton Drive, Breightmet, Bolton, was found guilty of allowing or causing the death of a child. Her sentencing was adjourned to a date yet to be fixed and she was remanded in custody.
Rigby, dressed in a grey suit, shirt and tie, put his head in his hands as the verdict was given. Smedley, dressed all in black and with her dark hair tied back, appeared to be struggling to hold back tears when the jury announced her guilty verdict.
Mr Justice MacKay told her: "I want you to understand that you stand in very real peril of a prison sentence as a result of this conviction. Don't have any delusions about it."
After the trial, Detective Constable Pam Chandler read a statement on behalf of Rio's family. It said: "Today we have got justice for our beautiful son, grandson, brother and nephew Rio. We have to live every day without Rio and for the rest of our lives we will never see him grow into a lovely young man. No matter how long that monster gets, he will still have a life."